1. Field of the Invention
The present invention relates to an image transfer type recording method and to kits for transferring and forming an image onto any type of image receiving medium such as plain paper, cloth, and plastic films.
2. Description of Related Art
As disclosed in U.S. Pat. No. 4,399,209, an image formation method is known for forming an image onto a developer medium using a photosensitive and pressure sensitive medium comprised of microcapsules which encapsulate a dyeprecursor, light hardening resin, and light polymerization initiator coated onto a base sheet, and a developer medium coated with a developer material which is color-reactable with the dyeprecursor encapsulated in the microcapsules on the base sheet. In this image formation method, the light hardening resin encapsulated in the microcapsules is selectively hardened by being exposed to light containing image information. Afterwards, the microcapsule layer of the photosensitive and pressure sensitive medium and the developer layer of the developer medium are superposed and are pressurized, and the microcapsules which are not hardened in the exposing operation are ruptured. As a result, a visible image is formed in the developer layer of the developer medium by color-reaction of the dyeprecursor which flows out from the ruptured microcapsules and the developer material of the developer medium.
However, in the above-mentioned image formation method, the image can be formed only onto the developer medium which has the developer layer, and not onto any other type of image receiving medium such as plain paper, cloths, plastic films or the like.
Therefore, in order to form an image onto any arbitrary type of image receiving medium, a method for adhering a developer medium on which an image can be formed onto any type of image receiving medium by using an adhesive layer is disclosed in U.S. Pat. No. 4,865,938. However, this adhesive process which uses the adhesive layer causes the following problems when the developer medium is adhered to an image receiving medium by the adhesive layer: the thickness of the image receiving medium increases and the weight of the image receiving medium becomes heavy.
In order to resolve this disadvantage, a further improved image transfer type recording system is provided, for example, in U.S. Pat. No. 5,019,475, filed by the same applicant as the present invention. In this improved system, a developer medium which includes a base sheet having a thermoplastic resin layer formed thereon, and a developer layer formed on the thermoplastic resin layer is used. The developer layer includes a developer and a binder for holding the developer together. An image is formed onto the developer layer of the developer medium. The developer layer of the developer medium on which the image is formed is then superposed over any type of image receiving medium. Next, the superposed developer medium and the image receiving medium are heated and pressurized by a heat roller. Then, the developer and the binder included in the developer layer melt, and the developer layer adheres to the image receiving medium. Moreover, the thermoplastic resin layer is also melted and the base sheet is peeled from the thermoplastic resin layer. As a result, the base sheet is peeled from the thermoplastic resin layer, and only the developer layer of the developer medium and the thermoplastic resin layer are adhered to the image receiving medium.
However, the above-mentioned system causes the following problems because the developer layer of the developer medium is adhered directly to the image receiving medium. The developer layer includes the developer and the binder. The developer layer and the image receiving medium are united to each other by the adhesive power of the binder included in the developer layer. The amount of binder included in the developer layer is about 10 weight percent of the entire developer layer. Therefore, the power for uniting the developer layer and the image receiving medium is not strong, and the developer layer peels off easily from the image receiving medium. In order to increase the power for uniting the developer layer to the image receiving medium, the percentage of the binder included in the developer layer is increased. However, when the percentage of the binder is increased, the percentage (or amount) of the developer is decreased, so that the developer layer is not colored easily and, consequently, a clear image cannot be formed onto the developer layer.
Moreover, when the receiving medium on which the colored image is formed is apparel, and when such apparel is washed, water or soapy water soaks into the developer layer from the rear side of the apparel and the color of the image is faded.